1. Technical Field
The present invention relates to a projector that projects an image on a projection surface by using a plurality of light sources and a light emission control method in the projector.
2. Related Art
There is a known projector of related art that modulates light from a light source based on an input image and projects the modulated light through a projection lens on a screen. It is further known that exchanging the light source in the projector changes the characteristics of the light source and hence the white balance, and that a time-varying change in a characteristic (illuminance) of the light source changes the white balance. A projector with a capability of adjusting an image actually projected on a screen to have appropriate white balance has therefore been proposed (see JP-A-2006-140839, for example).
Further, there is a known projector using a light source the luminance of which can be adjusted based on PWM (pulse width modulation) control, such as an LED and a laser (see JP-A-2010-051068, for example).
On the other hand, in a projector using a plurality of light sources, the light sources do not always have the same optical output characteristics. Specifically, when the light emission amounts of the light sources are changed, the actual light amounts sometimes do not change in the same manner. For example, when the light emission amounts of the light sources are changed in order to change the brightness on a projection screen, the white balance disadvantageously changes in some cases. As described above, in a projector using a plurality of light sources, appropriate adjustment of the white balance is not readily made because changing the light emission amounts of the light sources changes the white balance in a complicated manner.